I like how you used the value in SENTINEL as a counter. I'm going to use your entire modification, except including PE. I've quickly tested both fonts, sizes 1,2&4 and it works nicely! Thanks again!
The only problem I see is how you implement the PE into the PLTCHR to clear a character using a space. For example, if PXLCOL1,2,3=yellow, and SCRCOL1,2,3=blue, then when attempting to clear a character, instead of clearing it, there would be a yellow space on a blue background.
So I have removed that, and instead let the ATTBUTE routine manipulate TMPCOL1,2,3 to equal either PXLCOL1,2,3 or SCRCOL1,2,3. I'll post the 16bit version of the ATTBUTE routine when I get it done, hopefully soon.
BTW, I do see why you did this, I think. In order to not call ATTBUTE each and every time just to set a PE (plot or clear)...
What I need to do is incorporate
some or
most of ATTBUTE into the PLTCHR routine, using a 16bit register and test the individual 16bit settings everytime PLTCHR is called.
Code:
PLTCHR PHA ; Plot Character Subroutine variable (1-7) H and V size
TYA ; save all reg's
PHA
TXA
PHA
LDA #$2C ; Prepare TFT to Plot
STA DCOM
CACALC SEC
LDA CHR
CMP #127+1 ; an ascii char ?
BCS pltspc ; b: no (could be $0080 - $FFFF, don't know)
SBC #$20-1 ; first 32 ascii characters "undefined"
BCS nnull ; original char $20 - $7F now $00 - $5F (96 possible chars)
pltspc LDA #$00 ; make undefined char's a defined zero (space character)
nnull ASL A ; * 2
ASL A ; * 4
ASL A ; * 8
ADC CHRBASE ; add pointer to base either CA00 (C64) or CD00(3x5) (carry clear)
TAY
LDA CHRYLEN ; pattern rows either 8(c64) or 5(3x5)
STA PATROW
loop7 LDA XWIDTH ; plot row repeat count (1-7)
STA PIXROW
loop4 LDA $FFFF0000,Y ; $FFFFCA00(c64) or $FFFFCD00(3x5)
ASL A ;
ASL A ;
ASL A ;
ASL A ;
ASL A ;
ASL A ;
ASL A ;
ASL A ; shift out upper 8 bits, don't care for 8-bit byte character font
ORA SENTINEL ; $0080 (C64) or $0800 (3x5)
ASL A ; get a pixel
loop5 PHA ; save remaining pixel row data
LDX YWIDTH ; plot column repeat count (1-7) (same as PLTHGT?)
BCC xwnp ; b: clear ('blank')
xwp LDA TMPCOL1
STA DDAT ; plot RED pixel TFT data
LDA TMPCOL2
STA DDAT ; plot GREEN pixel TFT data
LDA TMPCOL3
STA DDAT ; plot BLUE pixel TFT data
DEX
BNE xwp
BEQ nxtpix ; b: forced
xwnp LDA SCRCOL1
STA DDAT ; plot RED "blank" pixel TFT data
LDA SCRCOL2
STA DDAT ; plot GREEN "blank" pixel TFT data
LDA SCRCOL3
STA DDAT ; plot BLUE "blank" pixel TFT data
DEX
BNE xwnp
nxtpix PLA ; get pixel row data back
ASL A ; another pixel to plot ?
BNE loop5 ; b: yes (sentinel still hasn't shifted out)
DEC PIXROW ; repeat this row ?
BNE loop4 ; b: yes
INY
DEC PATROW ; another pattern row to plot ?
BNE loop7 ; b: yes
PLA
TAX
PLA
TAY
PLA ;reload all reg's
RTS
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